239 research outputs found

    The N-end rule pathway controls multiple functions during Arabidopsis shoot and leaf development

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    The ubiquitin-dependent N-end rule pathway relates the in vivo half-life of a protein to the identity of its N-terminal residue. This proteolytic system is present in all organisms examined and has been shown to have a multitude of functions in animals and fungi. In plants, however, the functional understanding of the N-end rule pathway is only beginning. The N-end rule has a hierarchic structure. Destabilizing activity of N-terminal Asp, Glu, and (oxidized) Cys requires their conjugation to Arg by an arginyl–tRNA–protein transferase (R-transferase). The resulting N-terminal Arg is recognized by the pathway's E3 ubiquitin ligases, called “N-recognins.” Here, we show that the Arabidopsis R-transferases AtATE1 and AtATE2 regulate various aspects of leaf and shoot development. We also show that the previously identified N-recognin PROTEOLYSIS6 (PRT6) mediates these R-transferase-dependent activities. We further demonstrate that the arginylation branch of the N-end rule pathway plays a role in repressing the meristem-promoting BREVIPEDICELLUS (BP) gene in developing leaves. BP expression is known to be excluded from Arabidopsis leaves by the activities of the ASYMMETRIC LEAVES1 (AS1) transcription factor complex and the phytohormone auxin. Our results suggest that AtATE1 and AtATE2 act redundantly with AS1, but independently of auxin, in the control of leaf development

    The effects of siblings on the migration of women in two rural areas of Belgium and the Netherlands, 1829-1940

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    This study explores the extent to which the presence and activities of siblings shaped the chances of women migrating to rural and urban areas in two rural areas of Belgium and the Netherlands during the second half of the nineteenth and first decades of the twentieth century. Shared-frailty Cox proportional hazard analyses of longitudinal data from historical population registers show that siblings exerted an additive impact on women's migration, independently of temporal and household characteristics. Just how siblings influenced women's migration depended on regional modes of production and on employment opportunities. In the Zeeland region, sisters channelled each other into service positions. In the Pays de Herve, where men and women found industrial work in the Walloon cities, women were as much influenced by their brothers' activities. Evidence is found for two mechanisms explaining the effects of siblings: micro-economic notions of joint-household decision-making and social capital theory

    Consumer behaviour and the life-course: shopper reactions to self service grocery shops and supermarkets in England c.1947-1975

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    This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this recordThe paper examines the development of self-service grocery shopping from a consumer perspective. Using qualitative data constructed through a nationwide biographical survey and oral histories, it is possible to go beyond contemporary market surveys which give insufficient attention to shopping as a socially and culturally embedded practice. The paper uses the conceptual framework of the life-course, to demonstrate how grocery shopping is a complex activity, in which the retail encounter is shaped by the specific interconnection of different retail formats with consumer characteristics and situational influences. Consumer reactions to retail modernization must be understood in relation to the development of consumer practices at points of transition and stability within the life-course. These practices are accessed by examining retrospective consumer narratives about food shopping

    Gender differences in the impact of family background on leaving the parental home

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    We address the question to what extent characteristics of the family of origin influence the timing of leaving the parental home and to what extent these effects differ between men and women. We use data from the Netherlands Kinship Panel Study to examine the effects of parental resources, atmosphere in the family of origin and family structure on leaving home to live without a partner and leaving home to live with a partner. The results indicate that a pleasant atmosphere in the parental home decreases the risk of leaving home and living in stepfamilies or single-parent families increases this risk. The availability of parental resources leads to a decreased risk of leaving home at young ages, but an increased risk at later ages. Many of these effects are found for both men and women and for both pathways out of the home. Furthermore, we find evidence that women are affected more strongly by family background characteristics than men are

    A Strawberry KNOX Gene Regulates Leaf, Flower and Meristem Architecture

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    The KNOTTED-LIKE HOMEODOMAIN (KNOX) genes play a central role in maintenance of the shoot apical meristem. They also contribute to the morphology of simple and compound leaves. In this report we characterize the FaKNOX1 gene from strawberry (Fragaria spp.) and demonstrate its function in trasgenic plants. The FaKNOX1 cDNA was isolated from a cultivated strawberry (F.Ă—ananassa) flower EST library. The sequence is most similar to Class I KNOX genes, and was mapped to linkage group VI of the diploid strawberry genome. Unlike most KNOX genes studied, steady-state transcript levels were highest in flowers and fruits. Transcripts were also detected in emerging leaf primordia and the apical dome. Transgenic strawberry plants suppressing or overexpressing FaKNOX1 exhibited conspicuous changes in plant form. The FaKNOX1 RNAi plants presented a dwarfed phenotype with deeply serrated leaflets and exaggerated petiolules. They also exhibited a high level of cellular disorganization of the shoot apical meristem and leaves. Overexpression of FaKNOX1 caused dwarfed stature with wrinkled leaves. These gain- and loss-of-function assays in strawberry functionally demonstrate the contributions of a KNOX domain protein in a rosaceous species

    How Do Social Security and Income Affect the Living Arrangements of the Elderly? Evidence from Reforms in Mexico and Uruguay

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    It has been shown that the social security system and other sorts of government transfers have helped poor elderly people, such as widows, to live alone in the U. S. This paper investigates whether government financial support contributed to the increase in the probability of the vulnerable elderly living alone in Latin American countries as well. Specifically, the countries that in the 1980s experienced government reforms favorable to the vulnerable elderly, Mexico and Uruguay, are examined. It is concluded that the improvement of educational attainment was mainly responsible for helping the elderly poor to live alone in rural areas in Mexico, and not the government system. On the other hand, in Uruguay, for unmarried elderly females, the increase in social security income explains most of the increase in the probability of living alone

    Social change and the family: Comparative perspectives from the west, China, and South Asia

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    This paper examines the influence of social and economic change on family structure and relationships: How do such economic and social transformations as industrialization, urbanization, demographic change, the expansion of education, and the long-term growth of income influence the family? We take a comparative and historical approach, reviewing the experiences of three major sociocultural regions: the West, China, and South Asia. Many of the changes that have occurred in family life have been remarkably similar in the three settings—the separation of the workplace from the home, increased training of children in nonfamilial institutions, the development of living arrangements outside the family household, increased access of children to financial and other productive resources, and increased participation by children in the selection of a mate. While the similarities of family change in diverse cultural settings are striking, specific aspects of change have varied across settings because of significant pre-existing differences in family structure, residential patterns of marriage, autonomy of children, and the role of marriage within kinship systems.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45661/1/11206_2005_Article_BF01124383.pd
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